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// Portions Copyright 2024 Payara Foundation and/or its affiliates
package org.glassfish.security.services.impl;

import java.security.Principal;
import java.util.Set;
import java.util.logging.Logger;

import jakarta.inject.Singleton;
import javax.security.auth.Subject;
import javax.security.auth.login.LoginException;

import org.glassfish.security.common.Group;

import org.glassfish.security.common.UserNameAndPassword;
import org.glassfish.security.services.api.authentication.ImpersonationService;
import org.glassfish.security.services.common.Secure;
import org.jvnet.hk2.annotations.Service;

/**
 * The Impersonation Service Implementation.
 * 
 * @author jazheng
 */
@Service(name="impersonationService")
@Singleton
@Secure(accessPermissionName = "security/service/impersonation/simple")
public class ImpersonationServiceImpl implements ImpersonationService {

  static final Logger LOG = Logger
      .getLogger(ImpersonationServiceImpl.class.getName());

  @Override
  public Subject impersonate(String user, String[] groups, Subject subject,
      boolean virtual) throws LoginException {

    // Use the supplied Subject or create a new Subject
    final Subject _subject = 
      (subject != null)? subject: new Subject();
    
    if (user == null || user.isEmpty()) {
      return _subject;
    }
    
    // TODO - Add support for virtual = false after IdentityManager
    // is available in open source 
    if (!virtual) {
      throw new UnsupportedOperationException(
          "Use of non-virtual parameter is not supported");
    } else {
      // Build the Subject
      Set<Principal> principals = _subject.getPrincipals();
      principals.add(new UserNameAndPassword(user));
      if (groups != null) {
        for (String group: groups) {
          principals.add(new Group(group));
        }
      }
    }
 
    // Return the impersonated Subject
    return _subject;
  }
}
